A known device for this purpose consists of a tube-like probe. Attached to the anterior end of the probe are two one-armed lever-fashioned probe tips, which are movable about a common pivot. A rod-like translational element is movable in an axial direction within the probe. The anterior end of the translational element [i.e. the tip]slides past the pivot point of the probe tips in the frontal end of the probe. The anterior end of the translational element is connected to the probe tips via steering levers. The probe tips together with the steering levers form a joint-parallelogram (trapeziem). Accordingly, when the translational element is withdrawn with respect to the probe, the probe tips are spread apart; and when the translational element slides forwardly, the probe tips close.
To measure human or animal hollow organs, the probe is inserted into the hollow organ. The axial depth of penetration serves as an indication of the longitudinal extension of the hollow organ; and through the spreading of the probe tips, the transverse extension of the hollow organ can be explored. At the posterior end of the device there is an indicating device in the form of a similar joint-parallelogram with which a full scale diagram of the explored hollow organ can be made.
The device, which is primarily used for measurements of the cavum uteri of the human reproductive system, must possess relatively-long probe tips due to the joint-parallelogram which is used to spread the probe tips apart. This limits the determination of the transverse extension of cavum uteri, since the probe tips (when spread) will align with the inwardly convexly curved uterus wall. As a result, the head of the probe tip does not reach the uterus wall, especially in the region of the mouth of the fallopian tubes. This can lead to a false measurement.
Furthermore, with the known device the joints of the steering levers must be attached to the probe tips. This constitutes an extraordinary technical difficulty, since the combined cross sectional diameter of the closed probe tips must not exceed a maximum of 4 mm to warrant a safe insertion.
Finally, when the probe tips are fully spread apart, the anterior end of the probe will extend beyond the probe tips and touch the fundic roof of the uterus, such that a complete exploration is prevented.